Process of manufacturing products from cornstalks, sugar-cane, &amp;c.



No- 731,290. I

.-UNITED STATES Patented June 1 6, U503. PATENT OFFIC VIGGO DREWSEN, on NEW YORK, N. Y.

PROCESS OF MANUFACTURING PRODUCTS FROM CORNSTAL'KSI SUGAR-CANE. &c.

SPEGIFIC ATION forming part of Letters Patent No. 731,290, dated June 16, 1903.

Application filed April 13, 1903. Serial No. 152.321. (No specimens.)

To all whom, it may concern:

Be it known that I, VIGGO DREVVSEN, a citizen of the Kingdom of Norway, residing in the city of New York, county of Kings, and State of New York, have invented a new and useful Process of Manufacturing Products from Cornstalks, Sugar-Cane, and Analogous Pithy Stalks, of which the following is a specification. Y

The difficulty in preparing fibrous material (cellulose) or other products suitable for the manufacture of paper from these pithy stalks lies in the different character of the difierent parts of the stalk. A cornstalk proper,

namely, without leaves or husks, for instance, consists of two parts,which can be used by paper-manufacturersto wit, the outside shell and the pith. The shell has a character similar to wood and contains a high percentage of fibers,while the pith is spongy and consists principally of oblong cells. This is also true of the sugar-cane. The shell when treated with chemical substances, such as caustic soda or sulphurous acid and lime, yields a large proportion of fibers which are adapted for papermaking and produce an opaque sheet of paper.

The pith, on the other hand, when treated with the same substances disintegrates into cells, and the sheet of paper derived therefrom is transparent and resembles imitation parchment-paper. The concentration of the chemicals necessary to disintegrate these difierent parts of the stalk difiers very much. The

shell requires a much stronger cooking liquor and must be cooked for a longer time than is required in cooking the pith. If, there fore, the cornstalk is cooked whole with the intention of producing fibers, the strength of the cooking liqnorand the length of the cooking necessary for such purpose practically destroys the pith, which it is desirable to save, and this explains why the yield of paper-producing materials from the stalks is too small to make this process a commercial success. It has been proposed to overcome this difficulty by separating the fith from the shell mechanically and then cooking them differently in caustic-soda solutions separately and subsequently uniting them in the proportions desired, and efficient machines have been devised for this purpose; but the mechanical separation before cooking has been found to I have'discovered that I can separate the pith and shell and convert them into papermaking material in the following manner: I first split and cut up the entire stalk into pieces. I then place these pieces in a digester containingasolution so weakthat onlythepith becomes disintegrated and cook it for about, say, two hours, at a pressure of about sixty pounds per square inch. A solution of five pounds of caustic soda in seventy gallons of water is eificient, though I do not confine myself to this specific'strength nor to the exact length of cooking specified. Of course the shell willalso be partly cooked in this operation,but not sufficiently to disintegrate it into fibers. After cooking the pieces ofstalk long enough to disintegrate the pith the pressure is blown off from the digester and the contents are run down into a draining vat. colored liquor is allowed to run ofi and is washed out of the solid material and saved to be used for special purposes. The solid washed materials are then put th ough a scraping or raking machine that separates the cooked pith from the partly-cooked and hard shells and throws the two on a screen.

The pith-cells pass through the meshes of the ,screen and are collected on a wet-machine,

as it is termed in the art. The partly-cooked shells are carried by traveling belts, aprons, or buckets to a second digester, in which they are again cooked in a stronger solution of cooking liquor, so as to produce the fibrous material from the shell portion. A suitable strength of this solution is about seven pounds of caustic soda to eleven gallons of water. The cooking may take about .six

hours at a pressure of about sixty pounds per square inch. I do not, however, confine myself to the specific strength of cooking liquor and length ofcooking stated. The cooked fibrous material is now ready to be treated in the usual way, such as washing, beating, screening, 850., known to every pulp-producer. The cooked pith and the fibers from the shell may be afterward mixed in any desired proportions.

The dark- I Having thus described my invention, what I claim is a v 1. The process of manufacturing products from cornstalks, sugar-cane, and analogous pithy stalks which consists in, first, cooking the stalks in a disintegrating liquor of sufficient strength and for a sufficient time to disintegrate the pith only; second, separating the cooked pith of the shells; third, cooking'thc shells of the stalks in a disentegrating liquor of sufiicie'nt strength and 'for a sufficient time to disintegrate the-shell into fibers, sub? stantially as described.

2. The process of manufacturing products from cornstalks, sugar-cane, and analogous pithy stalks which consists in, first, slitting and dividingthe stalks into pieces; second,

cooking the pieces of stalks in a disintegratingliquor of suflicient strengthand for a sufficient time to disintegrate the pith only; third,

I separating the cooked pith from the shells;

fourth, cooking the shells of the stalks in a disintegrating liquor of sufiicient strength and for a suficient time to disintegrate the shells into fibers, substantially as described.

3. The process of manufacturing products from cornstalks, sugar-cane, and analogous pithy stalks which consists in, first, slitting and dividing the stalks into pieces; second, cooking the pieces of stalks in'a solution of caustic soda of sufficient strength and for a sufficient time to vdisintegrate the pith only;

third, separating the cooked pith from the shells; fourth, cooking the shells of the stalks in a solution of caustic soda of sufficient strength and for a sufiicient time to disintegrate the shells into fibers, substantially as described.

VIGGO' DREWSEN.

Witnesses:

J. E. HINDON HYDE,

EDMUND ELLSWORTH FIELD, J 1-, 

